单项选择题

While paralleling two AC generators using synchronizing lamps only, both lamps will go dark when the generators are （）.

A.running at the same speed
B.grounded
C.of the same polarity
D.in phase

点击查看答案&解析

上一题目录下一题

相关考题

单项选择题

Electric circuits are protected against overloads and short circuits by means of a/an （）.

A.circuit breaker
B.amplifier
C.diode
D.capacitor

单项选择题

Ambient temperature is the （）.

A.amount of temperature rise with no load
B.temperature of the compartment where the motor is located
C.normal operating temperature, less the room temperature
D.amount of temperature developed by an operating motor

单项选择题

You are attempting to parallel two AC generators and the synchroscope pointer is revolving in the slow directionThis indicates that the frequency of the incoming machine is （）.

A.higher than the bus frequency
B.lower than the bus freouencv
C.the same as the bus frequency but out of phase with it
D.the same as the bus frequency, and the circuit breaker may be closed at any pointer position